Separable equalized tandem axle wheel suspension



0d. 29, 1.963 K. W.TANTL1.NGER ETAL 3,103,822

SEPARABLE EQUALIZED TANDEM AXLE WHEEL SUSPENSION 'I 2 Sheets-Sheet l MWHQ NNN Nm@ @MMI Filed Aug. 28, 1961 0t- 29, 1963 K. w. TANTLINGER ETYAL 3,108,822

SEPARABLE EQUALIZED TANDM XLE WHEEL SUSPENSION Filed Aug. 28, 1961 2 Sheets-Sheet 2 United States Patent O 3,108,822 SEPARABLE EQUALLED TANBEM AXLF.

` WHEEL SUSFENS'IN Keith W. rIantlinger, Grosse Pointe Shores, Richard T.

Fujioka, xford, and Adrian F. Hulversan, Brayton Plains, Mich., assignars to lrnehanf Trailer Company,

Detroit, Mich., a carperation of Michigan Filed Aug. 28, 1961, Ser. N 134,25) 1 Claim. (Cl. 28d-164.5)

This invention relates generally to wheel suspensions and more particularly to separable equalized multiple axles for wheeled vehicles.

Heavy duty trailers of the type used for highway transport often employ a multiple axle wheel Suspension comprising two or more spaced independently sprung axles having load-equalizing connections therebetween. Such multiple axle wheel suspensions Substantially equalize the load on the axles during normal road operation. Conventionally, each axle has a pair of semi-elliptic springs fixedly secured thereto by, for example, U-bolt fasteners. Relatively simple torque arms maintain the axles in alignment. Generally, rockable equalizers engage adjacent ends of the front and rear semi-elliptic springs to equalize the load between the axles.

However, it often occurs that loading conditions of the trailer are Such that multiple axles are not required. Heretofore, no provision was made for change-over between Single and multiple axle wheel suspensions to accommodate changes in load, wherein load on the axles, in the multiple axle configuration, is equalized.

The present invention is directed to a wheel suspension comprising a plurality of like single axles that are usable individually as single axles or, alternatively, are joinable to form a load-equalizing multiple axle suspension. Further, coupling of the Single axles automatically equalizes the load between the axles of the multiple axle suspension.

It is to be noted that the multiple axle Suspension hereinafter described in detail is a tandem axle suspension. However, it will be obvious that the inveniton is applicable to effect equalization between any desired number of separable axles.

Accordingly, one object of the present invention is an improved multiple axle wheel suspension.

Another object is a separable equalized multiple axle suspension for a wheeled vehicle.

Another object is a Single axle wheel suspension that is relative.y easily coupled to a like single axle suspension to form a multiple axle suspension.

Another object is a single axle wheel suspension that is relatively easily coupled to a like single axle suspension to form a multiple axle suspension and wherein the load on the axles is automatically equalized upon coupling of the single axles.

Other objects and advantages of the present invention will be apparent in the following specification, claim and drawings, wherein:

FIGURE l is a side elevational view of a truck and trailer utilizing a single axle wheel suspension in accordance with an exemplary embodiment of the present invention;

FIG. 2 is a Side elevational view Similar to FIGURE l with a second axle joined to the first axle to form an equalized tandem axle suspension;

FIG. 3 iS a sectional view taken within the circle 3 of FIGURE l;

FIG. 4 is a sectional view similar to FIG. 3 showing the first step of coupling a Second single axle suspension to the first axle suspension of FIG. 3;

FIG. 5 is a sectional view taken within the circle 5 of FIG. 2 showing a pair of single axlescoupled in loadice equalizing relationship to form a tandem axle suspension; and

FIG. 6 is a fragmentary view of a modified coupling between the yoke and spring of adjacent single axle sus` pensions.

Referring to FIGURE 1 of the drawing, a trailer 20 is coupled through a fifth wheel 22 to a tractor 24 in the conventional manner. The trailer 20 is supported by a single axle wheel suspension, which is secured thereto by any suitable means.

When loading conditions of the trailer 20 require the addition of a second axle 30 to the trailer 20, coupling of the second single axle wheel Suspension 30 to the trailer 2li and first axle 30 automatically effects equilization of the load between the coupled Single axle suspensions 39.

As best seen in FIG. 3, a single axle wheel suspension 3d comprises a box-like frame defined by a pair of laterally spaced longitudinal Stringers 34, one of which is shown, and transverse Stringers 36 and 3S. For the purpose of simplicity, the structure associated with only one of the Stringers 34 will be described,it being understood that like assemblies are secured to each ofthe Stringers 34.

A downwardly depending hanger 44B is Secured to a front end 4l of the longitudinal Stringer 34 for the support of a yoke 42. The yoke 42 is of generally U-Shaped vertical transverse cross section, for a reason to be discussed. The yoke 42 is pivotally supported by Va shaft 44 that is accepted in complementary apertures 46 in the hanger 4t). The yoke 42 has an angularly upwardly extending plate Sli at a forward end 52 thereof to guide the yoke 42 over a complementary downwardly extending Surface 60 on a rearward end 61 of a leaf spring 62, as will be described. The other end'63 of the yoke 42 accepts a front end portion 64 of the spring 62.

When the wheel suspension Sii is utilized as a Single axle Suspension, load is transferred in part from the Stringer 34 to the spring 62 by a complementary bumper 7@ that is secured to the longitudinal Stringer 34 in superimposed relation to the front end portion 64 of the Spring 62. Load is transferred to the rear end 61 of the Spring 62 by a bumper '74 at a rearward end 75 of the longitudinal Stringer 34. A downwardly depending bracket Si? maintains the end portion 61 of the spring 62 in alignment with the Stringer 34.

A conventional axle is secured to the spring 62 intermediate the ends 61 and 64 thereof as by a pair of U-bolts h2 and 94. A downwardly depending bracket 96 underlies the axle 9i) and accommodates one end portion 9S of a radius rod lill), the other end portion 102 of which is pivotally secured to the hanger 40.

AS best Seen in FIG. 4, a pair of singlel axle wheel suspensions 36 are coupled to form an equalized tandem axle wheel Suspension by advancing the plate Sil of the yoke 42 on the rearward Suspension 3) into engagement with the cam surface 6i) on the rearward end 61 of the spring 62 of the front single axle wheel suspension 30. Thus, movement of the rearward wheel suspension 30 towards the frontal unit 30 biases the terminal end portion 6l of the spring 62 on the front unit 30 downwardly until the end portion 61 of the frontal spring 62 moves into the open end portion 52 of the yoke 42 on the rear wheel suspension 3G.

As best Seen in FIG. 5, the terminal end portion 61 of the spring 62 in the frontal axle unit 30 has moved into the open end portion 52 of the yoke 42, exerting a clockwise bias thereon about the pin 44 of the rearward axle unit Sii. A balancing counter-clockwise torque is elfected on the yoke 42 of therearward axle unit 30 by the front end portion 64 of the Spring 62 thereof. Thus, the yoke 44 on the rearward axle unit 30 carries an equalized load on opposite ends 52 and 63 thereof.

annessa n ea Referring now to FlG. 6 of the drawings, a pair of modiiied single axle wheel suspensions 16) are shown in the coupled condition to elliect equalizing of a load thereon. Each single axle wheel suspension 10th comprises a frame portion 162, a downwardly depending front hanger 11M, and a downwardly depending rear hanger 1de. A forward portion 108 of each frame 102 is provided with a downwardly depending yoke support hanger 119, upon which a yoke 112 is pivotally supported as by a pin 114. When the single axle wheel suspensions 1% are coupled, as shown in FIG. 6, a forward end portion 116 of the yoke 112 engages a rear end portion 11S of a spring 12) on the front axle suspension 100. The rear end portion 122 of the yoke 112 engages a front portion 124 of a spring 120 on the rearward axle suspension 10d. Thus, load on the springs 12@ of the forward and rearward wheel suspensions 169 is equalized by engagement of the rear and front end portions 11S and 124 thereof, respectively, with the front and rear end portions 116 and 122 of the yoke 112. Et is to be noted that the end portions 116 and 122 of the yoke 112 do not extend under the conventional bumpers 130 and 132 on the hangers 194 and 106, respectively, thereby simplifying the design of the suspensions 10i) and maximizing the clearance for vertical movement of the ends 118 and 124 of the springs 129.

lt is also to be noted that the forward wheel suspension 16? is provided with an alignment plate 13d that is engageable with a complementary alignment tongue 136 on the rearward wheel suspension 166 whereby, upon movement of the wheel suspensions 10i? into juxtaposed relationship, the frame portions 162 thereof are aligned horizontally. The rearward portion of the frame 102 is also provided with a pair of downwardly depending members 137 and 135 on opposite sides of the alignment tongue 136 to etTect lateral gathering of the suspensions 10i! as they move into engagement with one another.

An important feature of the herein disclosed method of coupling to achieve equalization is that coupling is accomplished by the relative movement between axles,

which can be produced by the tractive effort of the trac-V Y tor. Thus, no power source other than the tractor is required to effect coupling or uncoupling of the single axle suspensions. v

Also, it is to be noted that the single axle suspensions, when coupled in the multiple conguration, are no hop suspensions.

lt is to be understood that the specic constructions of the improved separable equalized multiple axle wheel suspension herein disclosed and described are presented for the purpose of explanation and illustration and are not yintended to indicate limits of the invention, the scope of which is defined by the following claim.

What is claimed is:

An equalized multiple axle wheel suspension comprising a pair of coupled substantially identical single axle Wheel suspensions, said single axle wheel suspensions comprising, respectively, a frame, a pair of elliptical springs having end portions, respectively, engageable with said frame, laterally aligned end portions of said springs having downwardly extending cam surfaces thereon, respectively, a wheel supporting axle disposed intermediate the end portions of said springs, respectively, and supported thereby, and a pair of yokes pivotally supported by said frame and engageable with the opposite end portions of said springs, respectively, said yokes having upwardly directed cam faces thereon, respectively, engageable with the cam surfaces, respectively, on the end portions of the springs on another of said single axle wheel suspensions for biasing the end portions of the springs on the other of the wheel suspensions out of engagement with the frame of the other wheel suspension to equalize the load on the axles of said wheel suspensions upon movement of said suspensions into the coupled condition.

References Cited in the le of this patent UNITED STATES PATENTS 2,665,142 Talbert lan. 5, 1954 2,912,251 Warren Nov. l0, 1959 3,064,772 Bohlen Oct. 17, 1961 

